This invention relates to mono-lens eyeglasses, particularly to one having its mono-lens alterable easily for various needs of users with no tools used.
First known conventional mono-lens eyeglasses shown in FIG. 4 includes a frame 90, a mono-lens 95, two temples 97 combined together. The frame 90 is provided with a long groove 91 formed in a lower edge for an upper edge of the mono-lens 95 to fit therein, and a recess 92 respectively formed in a rear side of two ends and a hole 93 bored in each recess 92. The mono-lens 95 gas a hole 96 corresponding to the hole 93 of the frame 90. Each temple 97 has a front end provided with a hole 98 corresponding to the hole 93 of the frame 3, and its front end fits in each recess 92 and is secured with the frame 90 with screw 94.
The first conventional mono-lens eyeglasses are especially used in sports activities, and various kinds of lenses are needed for various kinds of sports. So users change lenses by replacing processes, wherein tools such as drivers are required for removing screws. But where are drivers ? They cannot be carried with by sportsmen engaging in sports.
Next, second known conventional mono-lens eyeglasses shown in FIG. 5 has a more simple structure, including a frame 90 provided with a long groove 91 in a lower edge for an upper edge of a mono-lens 95 to fit therein, and two temples 97 combined with two ends of the frame 90. In use of the second conventional mono-lens eyeglasses if the mono-lens are frequently changed, tightness of the mono-lens against the groove may gradually deteriorated to result in the mono-lens falling off the groove easily in sport activities.